Breeze entity state doesn't change after saving - asp.net-web-api

My application uses BreezeJS, ASP.NET Web API and EF.
I'm trying to save an object using breeze, as follows:
var saveOptions = this.manager.saveOptions.using({ resourceName: "SaveLocationSettings", tag: clientId, allowConcurrentSaves: true });
var obj = self.manager.saveChanges(null, saveOptions).then(saveSucceeded, saveFailed);
I'm using a custom save method on the server side, which returns a SaveResult object. However, on the client side, the entity manager still maintains the modified state.
My controller on the Web API is a BreezeController.
According to the breeze documentation, if your custom method has the signature similar to the Breeze SaveChanges() method, it should work similar to SaveChanges() method. However, if I use the breeze SaveChanges(), the entity state gets updated properly. But my custom endpoint save does not update the entity state, although the data is saved in the database.
UPDATE:
After some investigation, I figured that this happens only with one entity type that goes to this particular save endpoint. Say, I have a 'location' object, with a collection of 'availability' associated with it, as follows:
Class Location {
public Location() {
this.Availabilities = new HashSet<Availability>();
}
}
Now from the client side, if I only change some property of the Location object, it handles the hasChanges property correctly. But if I change the Availability only or Availability along with another property of the location, then the hasChanges is not updated properly on client side.
This is my server side code that's called from the WebAPI controller:
public SaveResult SaveLocation(Location l, List<MaxAvailability> maxAvailability, int changedBy)
{
// Create a SaveResult object
// we need to return a SaveResult object for breeze
var keyMappings = new List<KeyMapping>();
var entities = new List<object> {l, maxAvailability};
var saveResult = new SaveResult() { Entities = entities, KeyMappings = keyMappings, Errors = null };
try
{
if (l.LocationId == -1)
{
// add new location
l.LocationId = this.AddNewLocationWithItsAssociatedData(l, maxAvailability, changedBy);
}
else
{
// do changes to the existing location
this.UpdateExistingLocationWithItsAssociatedData(l, maxAvailability, changedBy);
}
}
catch (DbEntityValidationException ex)
{
// Log the error and add the errors list to SaveResult.
// Retrieve the error messages as a list of strings.
saveResult.Errors = this.GetErrors(ex);
}
return saveResult;
}

I think I figured out the answer. It was due to some bad practice in my code. When modifying the availability of an existing location, instead of updating the existing record, I was deleting the existing record and adding a new one. This was causing the client side availability object and the database object to have two different states. Once it was resolved, the hasChanges() state was behaving as expected.

Related

retrieving id of notification that is inserted using PublishAsync method is not implemented

I am using ASP.NET Boilerplate with Code-First Entity Framework and MVC 5.
and in order to send a notification I am using the following code
public async Task SendNotification(Guid auditId, int auditNo, int? tenantId, long userId)
{
var notificationData = new LocalizableMessageNotificationData(
new LocalizableString(
"NotificationName",
EODAConsts.LocalizationSourceName
)
);
notificationData["auditNo"] = auditNo;
notificationData["auditId"] = auditId;
await _notificationPublisher.PublishAsync(NotificationName, notificationData, severity: NotificationSeverity.Error, userIds: new[] { new UserIdentifier(tenantId, userId) });
}
we know that sending the notification means adding it to AbpTenantNotifications and AbpUserNotifications ,but after sending it what is the way to retrieve inserted notification id in AbpTenantNotifications ,because PublishAsync method doesn't return any value
i mean what is the unique key in table AbpTenantNotifications which insures selecting specific one notification that is inserted after calling PublishAsync method
NotificationInfo only persist in the table for a short time only.
When you calls PublishAsync, NotifcationInfo is created immediately (see here).
Subsequently, it is consumed by NotificationDistributor.DistributeAsync and deleted right after converting NotificationInfo into TenantNotification & UserNotification (see here)
If you want to capture the TenantNotification when it is created, you can try with entity event handler (see here)

Compression response filter fails on breeze.js Metadata call

I have an http module where I'm adding a response filter below for compression. This works for all API calls except for 1, the call to MetaData. If I remove the [BreezeController] decoration it works fine. I think it has to do with action filter attribute that converts the string return type into an HttpResponse return type with string content.
The error I'm getting is " Exception message: The stream state of the underlying compression routine is inconsistent."
I've done some testing where a method thats defined to return an HttpResponse works fine. So I think its the scenario where the method is defined to return string, and then the action filter changes it to HttpResponse at runtime.
Any ideas how I can get this to work?
Here's the response filter being added in BeginRequest:
HttpApplication app = (HttpApplication)sender;
// Check the header to see if it can accept compressed output
string encodings = app.Request.Headers.Get("Accept-Encoding");
if (encodings == null)
return;
Stream s = app.Response.Filter;
encodings = encodings.ToLower();
if (encodings.Contains("gzip"))
{
app.Response.Filter = new GZipStream(s, CompressionMode.Compress);
app.Response.AppendHeader("Content-Encoding", "gzip");
}
Don't know the specifics of what you're doing but I know that the [BreezeController] attribute strips out filters and adds back just the ones that breeze wants.
One approach might be to define a separate controller (ModelMetadataController) that only serves the metadata. This controller doesn't have the [BreezeController] attribute; it's a plain old Web API controller.
Then you create a "Breeze controller" (ModelController) with all of the usual methods except the Metadata method.
You call the metadata controller from the client during app launch via MetadataStore.fetchMetadata just to get metadata.
Once you have populated a metadataStore in this fashion, you use it in your EntityManager which sends query and save requests to the "real" Web API data controller.
The client code might look something like this:
var ds = new breeze.DataService({
serviceName: 'breeze/Model' // the breeze query & save controller
});
var ms = new MetadataStore({
namingConvention: breeze.NamingConvention.camelCase, // assuming that's what you want
});
ms.addDataService(ds); // associate the metadata-to-come with the "real" dataService
var manager = new breeze.EntityManager({
dataService: ds,
metadataStore: ms
});
// the fun bit: fetch the metadata from a different controller
var promise = ms.fetchMetadata('breeze/ModelMetadata') // the metadata-only controller!
return promise; // wait on it appropriately

servicestack - caching a service response using redis

I have a servicestack service which when called via the browser (restful) Url ex:http://localhost:1616/myproducts, it works fine.
The service method has RedisCaching enabled. So first time it hits the data repository and caches it for subsequent use.
My problem is when I try calling it from a c# client via Soap12ServiceClient. It returns the below error:
Error in line 1 position 183. Expecting element '<target response>'
from namespace 'http://schemas.datacontract.org/2004/07/<target namespace>'..
Encountered 'Element' with name 'base64Binary',
namespace 'http://schemas.microsoft.com/2003/10/Serialization/'.
Below is my Client code:
var endpointURI = "http://mydevelopmentapi.serverhostingservices.com:1616/";
using (IServiceClient client = new Soap12ServiceClient(endpointURI))
{
var request = new ProductRequest { Param1 = "xy23432"};
client.Send<ProductResponse>(request);
}
It seems that the soapwsdl used is giving the problem, but I appear to have used the defaults as generated by servicestack..
Any help will be much appreciated.
Update
I was able over come this error by changing the cache code at the service end:
Code that returned error at client end:
return RequestContext.ToOptimizedResultUsingCache(this.CacheClient, cacheKey,
() =>
new ProductResponse(){CreateDate = DateTime.UtcNow,
products = new productRepository().Getproducts(request)
});
Code that works now:
var result = this.CacheClient.Get<ProductResponse>(cacheKey);
if (result == null)
{
this.CacheClient.Set<ProductResponse>(cacheKey, productResult);
result = productResult;
}
return result;
But I am still curious to know why the first method (RequestContext.ToOptimizedResultUsingCache) returned error at c# client?
But I am still curious to know why the first method (RequestContext.ToOptimizedResultUsingCache) returned error at c# client?
From what I can tell, the ToOptimizedResultUsingCache is trying to pull a specific format (xml, html, json, etc) out of the cache based on the RequestContext's ResponseContentType (see code here and here). When using the Soap12ServiceClient the ResponseContentType is text/html (not sure if this is correct/intentional within ServiceStack). So what ToOptimizedResultUsingCache is pulling out of the cache is a string of html. The html string is being returned to the Soap12ServiceClient and causing an exception.
By pulling directly out of the cache you are bypassing ToOptimizedResultUsingCache's 'format check' and returning something the Soap12ServiceClient can handle.
** If you are using Redis and creating your key with UrnId.Create method you should see a key like urn:ProductResponse:{yourkey}.html
Thanks for your response paaschpa.
I revisited the code and I was able to fix it. Since your response gave me the direction, I have accepted your answer. Below is my fix.
I moved the return statement from RequestContext to the response DTO.
Code which throws error when used via c# client (code was returning entire requestcontext):
return RequestContext.ToOptimizedResultUsingCache(this.CacheClient, cacheKey,
() =>
new ProductResponse(){CreateDate = DateTime.UtcNow,
products = new productRepository().Getproducts(request)
});
Fixed Code (return moved to response DTO):
RequestContext.ToOptimizedResultUsingCache(this.CacheClient, cacheKey,
() => {
return new ProductResponse(){CreateDate = DateTime.UtcNow,
products = new productRepository().Getproducts(request)
}
});

Can I switch use of 'entities.SingleOrDefault' ==> 'entities.Find' without hazards?

In my WCF service's business logic, most of the places when I need to locate an entity, I use this syntax:
public void UpdateUser(Guid userId, String notes)
{
using (ProjEntities entities = new ProjEntities())
{
User currUser = entities.SingleOrDefault(us => us.Id == userId);
if (currUser == null)
throw new Exception("User with ID " + userId + " was not found");
}
}
I have recentely discovered that the DbContext has the Find method, and I understand I can now do this:
public void UpdateUser(Guid userId, String notes)
{
using (ProjEntities entities = new ProjEntities())
{
User currUser = entities.Find(userId);
if (currUser == null)
throw new Exception("User with ID " + userId + " was not found");
}
}
Note : the 'userId' property is the primary key for the table.
I read that when using Find method entity framework checks first to see if the entity is already in the local memory, and if so - brings it from there. Otherwise - a trip is made to the database (vs. SingleOrDefault which always makes a trip to the database).
I was wondering if I now will convert all my uses of SingleOrDefault to Find is there any potential of danger?
Is there a chance I could get some old data that has not been updated if I use Find and it fetches the data from memory instead of the database?
What happens if I have the user in memory, and someone changed the user in the database - won't it be a problem if I always use now this 'memory' replica instead of always fetching the latest updated one from the database?
Is there a chance I could get some old data that has not been updated
if I use Find and it fetches the data from memory instead of the
database?
I think you have sort of answered your own question here. Yes, there is a chance that using Find you could end up having an entity returned that is out of sync with your database because your context has a local copy.
There isn't much more anyone can tell you without knowing more about your specific application; do you keep a context alive for a long time or do you open it, do your updates and close it? obviously, the longer you keep your context around the more susceptible you are to retrieving an up to date entity.
I can think of two strategies for dealing with this. The first is outlined above; open your context, do what you need and then dispose of it:
using (var ctx = new MyContext())
{
var entity = ctx.EntitySet.Find(123);
// Do something with your entity here...
ctx.SaveChanges();
}
Secondly, you could retrieve the DbEntityEntry for your entity and use the GetDatabaseValues method to update it with the values from the database. Something like this:
var entity = ctx.EntitySet.Find(123);
// This could be a cached version so ensure it is up to date.
var entry = ctx.Entry(entity);
entry.OriginalValues.SetValues(entry.GetDatabaseValues());

WCF Data Service - Add Object With Related Object

I have the following situation, I have a WCF Data Service with User objects and message objects and the message object has two relations to user, a sender and a receiver.
When I try to add a new Message object the related users are left null
Message message = new Message();
message.text = InputText; // string
message.Sender = Sender; // User object
message.Receiver = Receiver; // User object
context.AddToMessages(message);
context.BeginSaveChanges(new AsyncCallback((result) =>
{
// Some code
}));
Now the Sender and Receiver will be null. When I try to set a link before the BeginSaceChanges like this I get the error "InvalidOperationException: The context is not currently tracking the entity."
context.AddToMessages(message);
context.AddLink(message, "Sender", message.Sender);
context.AddLink(message, "Receiver", message.Receiver);
context.BeginSaveChanges(new AsyncCallback((result) =>
{
// Some code
}));
How do I make sure the relations are created properly?
Thanks to Pratik I found the solution. I had to use attach the already existing users Sender and Receiver to the context first because they weren't tracked (and added a if if they are on the second call). Then I add the message and use SetLink to set the link to both users (instead of AddLink)
if(context.GetEntityDescriptor(message.Sender) == null)
context.AttachTo("Users", message.Sender);
if (context.GetEntityDescriptor(message.Receiver) == null)
context.AttachTo("Users", message.Receiver);
context.AddToMessages(message);
context.SetLink(message, "Sender", message.Sender);
context.SetLink(message, "Receiver", message.Receiver);
context.BeginSaveChanges(new AsyncCallback((result) =>
{
// Some code
}));
I believe you need to use the DbSet.Attach method instead. I assume you use Entity Framework on the back end here.

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